The present invention is related to a method and apparatus for performing maintenance and repair on the outer surface of a satellite while the satellite is in orbit. More particularly, the present invention is comprised of movable pincers for latching onto the pliable protective fabric covering the satellite and moving the invention across the fabric, whereby the invention can carry and transport a proximity repair micro-satellite across the fabric to a location requiring repair or maintenance.
Satellites begin to deteriorate after launch, whereupon they are exposed to the deleterious effects of cosmic radiation, solar winds and electro-magnetic radiation while passing through the Van Alen belt. Over time, flecks of space debris may damage the satellite's surface. Continued damage may ultimately corrupt the satellite's hardware and electronic systems. Since there are no means to effect repairs or perform maintenance, satellite components will inevitably begin to malfunction or fail entirely. Depending on the system, the foregoing could render a satellite useless. Thus, for want of a minor repair or routine maintenance, a multi-million dollar satellite could be rendered useless and reduced to orbiting space junk.
Multi-layered insulation (hereinafter called “MLI”) is a manufactured material used to cover nearly the entire body of objects placed in orbit, i.e., satellites, and is presently the only known means of providing limited protection to such objects. MLI reflects harmful incident radiation, and also insulates the object from the cold of outer space by using multiple radiation-heat transfer barriers to retard the flow of energy that would otherwise cause damage. Beta cloth is one example of an MLI. It is an inorganic, fiberglass woven cloth impregnated with Teflon® polytetraflouroethylene resin (Teflon is a registered trademark owned by DuPont), and perforated to prevent ballooning. As an outer cover, the Beta cloth MLI has a nominal thickness of 0.008 inches and is rated with a tensile strength of about 90 lb/inch against warping. Its minimum shear strength is 1.8 pounds and it can maintain the foregoing tensile and shear strengths at a temperature of up to 400° F. However, regardless of its composition, MLI is not impermeable, and damage to the satellite nonetheless occurs. Maintenance of an orbiting satellite would also enhance its longevity.
The XSS Micro-satellite series is the Air Force Research Laboratory's sequence of on-orbit experiments to develop a logistics and servicing capability for orbiting satellites. As the name would imply, micro-satellites (hereinafter referred to as “nanosats”) are small, agile and compact. They are fully equipped with on-board avionics, propulsion and high-resolution cameras allowing a highly maneuverable nanosat to perform close-proximity inspection. It is the intent of aerospace leaders to expand the capability of such nanosats to include task-specific resources and tools, thereby providing it with the capability to perform maintenance and repair. Such modification of nanosats would permit them to extend the life and performance of an orbiting satellite at substantially less cost, and in less time, than by preparing and launching a replacement satellite from the earth.
Whatever the specific form or composition of the MLI, this protective fabric should provide a medium having sufficient pliability for the present invention to grasp onto and provide transport for a nanosat across the exterior of an orbiting satellite, as will be hereinafter discussed in detail.
Despite the availability of MLI as a means of protection for satellites, there is still a need in the art for means to perform exterior maintenance and repair while the satellite is in orbit. The present invention provides means for transporting a nanosat capable of performing maintenance and repair, across the MLI covering an orbiting satellite. The present invention thus fulfills the aforementioned need in the art.